Watch casing



FIG. 1 is a top plan of a watch casing, my new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a front side view thereof;

FIG. 4 is a rear side view thereof;

FIG. 5 is a right side view thereof; and,

FIG. 6 is a left side view thereof. 

The ornamental design for a watch casing, as shown. 